|Quadrangle map, 1:250,000-scale||MF|
|Quadrangle map, 1:63,360-scale||D-3|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This site is a small bight on the northeast tip of Russell Island (Kimball and others (1978, figs. C45 and C55). The location is accurate within 0.10 mile. Another vein cropped out 1000 feet west-northwest of located vein. The locality is number 29 of Cobb (1972).|
Russell Island is underlain mainly by granodiorite of Cretaceous age (Brew and others, 1978). On the northeastern part of the island, quartz veins as much as about 0.5 feet wide occur in ankeritic (iron-stained) zones as much as 4 feet thick that cut the granodiorite. The main vein occurrence has an estimated length of 280 feet on the island. It strikes N. 15 degrees E. and is nearly vertical. It extends across the small peninsula between shorelines of Glacier Bay at the northeast tip of Russell Island (Kimball and others, 1978, fig. C55). The quartz veins within the ankerite shear zone contain ankerite, pyrite, pyrrhotite, sericite, dolomite, calcite, and traces of scheelite. The pyrite contains native gold particles visible microscopically. Two additional, narrow iron-stained vein zones are 1,000 feet west-northwest of the main vein zone. The Russell Island occurrences appear to represent the approximate northeast limit of the Reid Inlet gold area.Channel samples of selected veins contained more than 5 ounces per ton gold, and a weighted sample reduced to a 4-foot mining width contained 0.35 ounce per ton gold.
|Geologic map unit||(-136.814975704373, 58.9410005968491)|
|Mineral deposit model||Low-sulfide gold-quartz vein (Cox and Singer, 1986; model 36a).|
|Mineral deposit model number||36a|
|Age of mineralization||Late Cretaceous or younger.|
|Alteration of deposit||Granodiorite has been altered; alteration products include chlorite, sericite, introduced quartz, and probably ankerite or dolomite.|
|Workings or exploration||
Surface exposures only. Channel samples of selected quartz veins contain as much as 5.81 ounces per ton gold, 2.64 ounces per ton silver, 890 ppm lead, 550 ppm zinc, and less than 50 ppm tungsten. (Five of fifteen samples from the veins show a trace of tungsten as does one of two samples from the vein occurrence 1000 feet to the west-northwest.) Weighted values for 4-foot mining widths range from 0.02 to 0.35 ounce per ton gold and from 0.02 to 0.17 ounce per ton silver (Kimball and others, 1978, p. C238-241).The occurrence may have been discovered by the U.S. Geological Survey in 1966; MacKevett and others (1966) reported a narrow quartz vein at the site contained 0.844 ounces of gold per ton.
|Indication of production||None|
Additional commentsArea warrants further exploration; it is within Glacier Bay National Park and Preserve.
Brew, D.A., Johnson, B.R., Grybeck, D., Griscom, A., Barnes, D.F., Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources of the Glacier Bay National Monument Wilderness Study Area, Alaska: U.S. Geological Survey Open-File Report 78-494, 670 p., 7 sheets.
Cobb, E.H., 1972, Metallic mineral resources map of the Mount Fairweather quadrangle, AK: U.S. Geological Survey Miscellaneous Field Study Map MF-436, 1 sheet, scale 1:250,000.
Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources, in Brew, D. A., and others, Mineral resources of the Glacier Bay National Monument wilderness study area, Alaska: U.S. Geological Survey Open-File Report 78-494, p. C1-C375.
|Reporters||C.C. Hawley (Hawley Resource Group)|
|Last report date||4/8/1999|